I am on Amtrak, and the 30 Knorr and/or Epic Systems have the Suppression position before the Full Service position. The Suppression position makes a 17 pound reduction, (full service is approximately 26 pounds) and nullifies the PCS with throttle handle in idle. It was moved, because there isn't a justifiable reason to grind a train to a stop, for a penalty that occured due to a few mph overspeed, or a tardy acknowledgement of an alertor/CSS. As long as you can get the handle to Suppression, and recover the penalty before you stop AND as long as you have enough air after doing this to control the train in accordance with the next block signal, it's doable. A penalty doesn't give you a "full service" application, it merely makes an "unwanted"
service reduction, that will continue until you overcome the penalty situation. ( Of course, those freight type 26 and 30 systems do have suppression just before full service, and as you know, there isn't a pressure difference between those 2 positions. They should both make an approximate 26 pound reduction) If left unchecked, the penalty would take the EQ to zero, at a
service rate. We are trained to recover from a penalty "on the fly" and to keep the train moving, within the restrictions imposed by the reason for recieving the penalty in the first place. Notice our Suppression is only 17 pounds, just under the mandated stop, for 18 pounds!( Some TTSI's/AB&TH's might impose a full stop, no matter the reason for the penalty, but this is done on a railroad by railroad basis) Not acknowledging an alertor at 79 mph isn't reason to stop as train, but you might have to explain the penalty to your crew, or the RFE if he downloads your engines.........